Character's Underlying Mesh is showing through top mesh of Jeans
You could delete this part of your mesh. If you prefer a non-destructive way you could give your object a Mask modifier:


In Edit mode, select the part you want to make invisible, assign it to a group.
Back in Object mode, give your object a Mask modifier, in the Vertex Group field, choose the group you've created, click on the arrow on the right to invert the masking effect.